Cây hồ tiêu bệnh hại và biện pháp phòng trừ

BUI
CACH TUYEN - LE OJNH OON
BENH HAI VA BIEN PHAP PHONG TRll
BUI CACH TUY^N - LE
OJNH
DON
CAY HO
TIEU
BENH
HAI VA
BIEN
PHAP PHONG TRQ
NHA
XUAT BAN NONG NGHIEP
TP. Ho Chi
Minh-2013
1*
-
ii
V
I
MVC LVC
L6i gioi thifu xi
L6i noi dau xii
I. Sff lirgc ve cay ho tieu 1
II.
Dac diem hinh thai cua cay ho tieu 5
1. Dac dilm chung 5
2.
Dac diem nong hoc cua cay ho tieu 5
3.

Dac diem hinh thai cay ho tieu 6
III.
Bfnh hai tren cay ho tieu tai Vift Nam 11
1.
Benh Phytophthora tren ho tieu 11
Mo ta trieu chung va tac hai cua benh 12
Tac nhan gay benh va dac diem gay benh 15
2.
Benh vang la 19
Mo ta trieu chung va tac hai cua benh 19
Tac nhan gay benh va dac diem gay benh 20
3.
Benh do tuyen trung 21
Mo ta trieu chung va tac hai cua benh 21
Tac nhan gay benh va dac diem gay benh 22
4.
Benh do vi rut 28
Trieu chung benh do vi nit gay ra 28
Tinh trang benh vi nit tren cay ho tieu 31
Xac dinh tac nhan vi nit bSng ky thuat phan tu 32
Xac dinh phuomg thiic Ian truy6n benh vi nit 33
Tac hai cua benh vi nit tren cay ho tieu 34
iii
4
5. Benh sai chi (mang nhen) 36
Mo
ta
trieu
chung va tac hai
ciia

benh 36
Tac nhan gay benh va dac diem gay benh 37
6. Benh d6m tao (dom rong) 38
Mo
ta
trieu
chung va tac hai cua benh 38
Tac nhan gay b?nh va dac diem gay benh 39
7. Benh than thu (kho la) 41
Mo
ta
trieu
chung va tac hai
ciia
benh 41
Tac nhan gay benh va dac diem gay benh 42
8. Benh tren hat sau thu hoach 43
Mo
ta
tri?u
chung va tac hai cua benh 43
Tac nhan gay benh va dac diem gay benh 43
IV.
Phong benh va
trir
tac nhan gay b^nh 48
1.
Dich
te hoc
ciia

benh hai tren cay ho
tieu
48
2.
Nh&ng
giai
phap
chinh
trong han che
dich
benh tren ho
tieu
50
3. Mot so bien phap cu the 63
Tai
lieu tham khao 71
iv
DANH SACH BANG
Blngl:
Dien tfch trong cay ho tieu tren the gidi (hecta)
,
Bang 2: San \uang hat ho tieu tren the gi6i (Tan)
Bang 3: Dien ti'ch cay ho tieu tai
6
tinh trong tieu chinh d Viet nam (VPA,
2011)
Bang 4: Mot so chi tieu so sanh hinh thai
P.
capsici phan lap
d

vudn tieu
thuanva xen ca phe
Bang 5: Nguon
P.
capsici trong vudn ho tieu bi benh chet nhanh vao mua
kho (thang 2/2011)
Bang 6: SUtich ICiy nguon
P
capsici trong mua kho va mUa
d
hai mo hinh
trong ho tieu nam 2007 (Iran Thi Hadng, 2009)
Bang 7: Phan Cfng cua mot so cay chi thi vdi Meloidogyne spp. phan lap tCr
re nhieu giong ho tieu khac nhau trong thf nghiem chung benh
BIng
8:
Mat
so
tuyen trung Meloidogyne spp.
va
Tylenchulus sp. trong
vungrehotieu
Bang
9: Ti le (%)
la tieu benh theo tC/ng trieu chu'ng
d
cac vung dieu
tra
nam 2004
Bang 10:

Ti le (%)
tru tieu benh theo tCrng trieu chu'ng
va
tuoi cay
d
cac
vung dieu tra nam 2004
Being 11: Ket qua phan tich mau benh bang ELISA
Bang 12:
Ti
le xuat hien TMV trong cac trieu chufng benh (So lieu dieu
tra
nam 2003)
Bing 13: Sii Ian truyen vi rut qua hom giong trong giam canh tieu
VTnh
Linh
theo trieu chu'ng
Bang 14: So sanh so chum trai/canh, chieu dai chum, so trai va kich thi/dc
hat trung binh tren tieu Vinh Linh 4
-
5 tuoi trong tai huyen Chau
Dijfctinh Ba Ria-VungTau
Being 15: So
sanh
nang suat
tieu
hat
giu'a
cay
tieu

benh vi
rut
nang va nhe
tren
giong
Vfnh
Linh
4
-
5
tuoi
trong
tai
huyen
Chau
Dufc,
tinh
Ba
Rja-Vung
Tau
B^ng 16:
SU
tap
nhiem
vi sinh
tren
hat ho
tieu
I<h6
ton

trCf
tai
B^ Rja - Vung
Tau (dieu
tra
thang
5/2012)
BSng
17: Ty le (%)
hat
tieu
tai
Ba Rja - Vung Tau nhiem cac
loai
Aspergillus
vi
DANH
SACH
HlNH
ANH
Hinhl:
Cac sin pham
sCr
dung
tCf
hat
ho
tieu
Hinh2:
Dien

tfch
cay ho
tieu
va
sU
phan
bo
theo
dja phu'ong
Hinh3:
Cac loai
re
cay
tieu
Hinh
4:
Choi
than
non mau do nhat
Hinh 5:
Mau
sSc va hinh dang ngpn non cua ho
tieu
Hinh 6: Cac loai
canh
phat
trien
tren
cay ho
tieu

Hinh 7: Cac dang la
tieu
Hinh 8:
Chum
hoa va hoa ho
tieu
Hinh 9a,
9b:
Cac dang
trai
tieu
Hinh 10: Cac dang
trieu
chu'ng benh do
Phytophthora
capsici
gay
ra
tren
la
ho
tieu
Hinh
11:
Trieu chu'ng benh do
Phytophthora
capsici
gay
ra
tren

ho
tieu
Hinh 12: Trieu chufng benh
Phytophthora
capsici
tren
than
tieu.
Hinh 13: Cay ho
tieu
bj benh chet nhanh
Hinh 14: Cay
ho
tieu
bj benh chet nhanh con sot
lai
tren
cay choai va lay Ian
thanh
cum
tren
vudn
tieu
Hinh 15: Trieu chufng gay ra
tren
cac mau la
tieu
dung de "bay P
capsici"
trong

dat,
nhiet
do phong sau 4
ngay
Hinh 16: Trieu
chufng
"teo
t6p"cS
chum
trai
tieu
xanh la dau hieu nhan
biet
cay bj benh chet
nhanh,
khong the phuc hoi
Hinh 18: Hoi
chCrng
vang la
Hinh 19: Mau nam
Fusarium
sp.
tren
moi
triTdng PDA phan lap tCrvUdn ho
tieu
bj benh
thoi
re vang la (A, B). Cay
tieu

sau khi chung nam
duoc
each
ly (C), cay ho
tieu
bj nhiem benh vang la sau chung 14
ngay
(D).
vii
Hinh 20: Dai bao
tCr
va
tieu
bao tCr nam Fusarium spp.
Hinh
21:
Phan
ufng cua mot so cay
l<y
chCi
chi
thi
cho
siigay
benh cua tuyen
trung
Meloidogyne spp. phan lap tC/ re ho
tieu
Hinh 22: Su djnh cU cua Meloidogyne spp.
trong

re ho
tieu
Hinh 23: Re cay ho
tieu
bj u budu do tuyen
trung
Meloidogyne spp.
Hinh 24:
Tuyen
trung
tren
cay ho
tieu
Hinh 25a, 25b: Cac dang benh do vi rut gay ra
Hinh 26:
Benh
vi
rut
tren
cay ho
tieu
Hinh 27: Dien di
DNA-PCR
vdi cac primer chuyen biet giup xac dinh sii hien
dien
cua vi rut
PYMoV
trong
la ho
tieu

benh
Hinh 28: Cay ho
tieu
nang suat cao, khong benh (A), mot vai la c6
trieu
chCrng
vi
rut
tim
thay
trong
tan la (B)
Hinh 29a, 29b: Trieu chufng va tac hai cua nam gay benh sdi chi (mang nhen)
tren
cay ho
tieu
Hinh 30:
Mufc
do benh dom tao
tren
trai
tieu
chUa
chi'n theo dp cao cua cay
Hinh
31:
Trieu chufng benh dom tao (dom rong)
tren
cay ho
tieu

Hinh 32: 6 tao gay benh dom
tren
ho
tieu
Hinh 33a,33b:
Benh
than tha
tren
cay ho
tieu
Hinh 34: Cay ho
tieu
bj benh vang la va than
thii
v6i vet benh tai chop la
Hinh 35: Nam Aspergillus sp.
Hinh 36: Nam Penicillium citrinum
Hinh 37: Nam
Fivsanum
sp.
Hinh 38: Nam
Mucor
sp.
Hinh 39:
Trai
bat (A), Iu6i (B) cho thu hoach ho
tieu
nham han che
SLftap
nhiem

va giam cong thu hoach
Hinh 40a: Trong cay lac dai Arachis pintoi (A) va c6 Stylosanthes gracilis (B)
giQa
cac hang cay
tieu
giup
giCf
am
vUdfn
vao mua kho, han che xoi
mon
dat vao mua maa.
viil
Hinh 40b: Trong cay lac dai Arachispintoi (C)
giQa
cac hang cay
tieu
giup giuf
am vudn vao mua kho, han che xoi mon dat vao mua mUa
Hinh
41:
SU che phu cua cay lac dai cho cay ho
tieu
Hinh 42: He
thong
tudi
nho giot giup
tiet
kiem
nUdc

va dim bao dp am dat
vao mua kho.
Hinh 43a, 43b:
Vadn
aom cay con va san xuat cay ho
tieu
giong
Hinh 44a, 44b: Cac dang tru choai cho cay ho
tieu
Hinh 45: Cat tia cac
canh
vung sat goc
tieu
tao sU thong thoang; B:
Vadn
ho
tieu
da tao sU
thong
thoang
Hinh 46: Vudn ho
tieu
dUpc
sii dung thCr nghiem che pham vi sinh BCF
chLfa
Bacillus subtilis tai
Chau
DiJc,
Ba Rja - Vung Tau, 2012
Hinh 47a: Cay

tieu
khong benh va bp re cay khong benh
Hinh
47b:Cay
nhiem Phytophthora
capsici\/6\p re bj huy hoai
Hinh 47c: XCr ly Trichoderma virens
(T.41)
han che siJ xam nhiem gay hai cua
Phytophthora
capsici duy
trl
sU phat
trien
cua cay
tieu
Hinh 48: A: Tao ranh bon phan quanh goc
tru
choai, ngoai tan cay
tieu
0,5
met;
B:Tadi
dung dich thuoc benh theo nong dp khuyen cao vao
goc
tieu
tCr
3
- 5 lit giup thuoc ngam sau vao he thong re
Hinh 49: IVlpt so mo hinh

canh
tac ho
tieu
tai Ba Ria - Vung Tau
Hinh 50: Tan du benh chet nhanh cay ho
tieu
Hinh
51:
Cay ho
tieu
Vinh
Linh
dUpc
ghep
tren
goc
tieu
dai
Hinh 52: San xuat cay ho
tieu
qua nuoi cay mo nham tao cay
sach
vi rut
Hinh 53: Ky
thuat
dudng
canh
tieu
luon cho lam hom giong
Hinh 54: Cay giong khoe manh diipc chuan bi

trong
Hinh 55: Tao vanh dai bon phan hQu co (10
kg/cay)
va micromate (50
g/cay)
Hinh 56: A: XCf ly thuoc trUc
tiep
tren
goc than cay benh; B: Quet thuoc goc
dong
len goc than va vung re sau khi
dapc
cat tia lam goc than
thongthoang
ix
Hinh 57: Ho trSng tieu Ba Ria - Vung Tau tham quan mo hinh trong tieu vai
try choai la
tru
be tong
Hinh 58: Lich thuc hien cac tac dong trong bao ve thuc vat va phan bon cho
cay ho tieu trong tai Ba Ria - Vung Tau
Hinh 59: Ho tieu trong tren tru choai song cay keo dau (Leucaena
leucocephala)
Hinh 60: Sir phan bo cua benh va tac nhan gay bfnh tren cay ho tieu
Hinh
61:
Bo sung Can-xi va Ma-gie giiip tang so trai/chum va so chum
trai/canh
L(i\G\($\J\\\%\}
Tieu

la cay
trong
sieu
loi nhuan, tuy nhien ngadi
trong
tieu gap rat
nhieu rui ro, vi cay tieu c6 nhieu benh hai. Hon the nufa, nhieu nam qua
trong
tieu 6
nUdc
ta
chu yeu tham
canh
b3ng bien phap hoa hoc (phan b6n
va thuoc bio ve thUc vat hoa hoc) lam cho benh hai
cang
them pha hai
nang ne.
Quyen
sach"Cay
ho tieu -
Benh
hai va bien phap phong tru"da gi6i
thieu
tom
t^t
day du dac diem
sinh
hoc, nong hoc va nhufng benh hai chinh
cua cay ho

tieu.Tac
gii da phan tich ro dac diem
sinh
hoc,
sinh
thai cua cac
nhom ky
sinh
gay benh hai chinh nhU: Nhom nam gay benh chet nhanh,
chet cham, cac loai tuyen
trung
gay hai tren ho tieu c6
trong
dat va nhom
benh do nhieu tac
nhan
virus
gay ra.
Siitac
dong qua lai, tuong tac
giCa
cac
nhom ky
sinh
va cay
trong
tren co sd bien phap
canh
tac theo
htfdng

tham
canh
hoa hoc, thieu ben vijfng da lam benh hai them nghiem
trong,
nhieu
vu'6n tieu bj benh chet hang loat.
lii nhufng dac diem cua cay tieu va nhufng benh hai chinh co tCr
trong
dat, tac gia quyen
sach
da de xuat bien phap phong
trCf
theo
IPM chu
yeu tren nen
canh
tac theo hadng hOfu co, bio ve do phi
trong
dat, lam co
s6 cho
quan
the vi
sinh
vat co fch va doi khang phat
trien
du
sufc
khong che
benh hai co
nguyen

nhan
tCr
trong
dat, va dong
th6i
cay tieu phat trien
kh6e
manh
du
sufc
de khang lai benh hai la y tudng rat tien
tien,
co co sd
khoa
hoc.
Bien
phap quin ly djch hai
tong
hop cua tac gii de xuat dang la
djnh hadng cua nhieu mo hinh san xuat tieu ben vijfng cho cac vung
trong
tieu chinh cua ca nude.
Sach
la tai lieu
chuyen
khao
rat t6t cho nghien cufu, dao tao va
giup cho ngudi san xuat tang nang suat, sin luong va pha'm chat sin
pham ho
tieu.

Tran
trong
gidi thieu den ban doc.
GS.TS.
Nguyen
Thor
xi
iCf\I DAU
Benh tren
cay ho
tieu
da
dugfc nghien cufu
vao
nhCng
nam
80 khi
hat
ho
tieu Viet
Nam
daac
chu
y
tren
thi
trUdng hang nong
san va
dong thdi
xuat hien nhieu

bao cao ve
hien tuang
cay ho
tieu chet hang loat.
Cac
nghien
CLTU
ve
benh
hai ho
tieu dUgfc
cap
kinh
phi tii
nguon
dja
phuong
hoac
cap Bo va Nha
nUdc. Nhieu
ket qua
nghien cufu
da
duac
tong
ket,
pho
bien,
LTng
dung,

dem
lai
hieu
qua ky
thuat
va
kinh
te cho
ngadi trong tieu
va
gia
tang
san
iupng
hat
tieu xuat khau
dem
ngoai
te
ve cho
dat
nadc.
Npi dung trinh
bay
trong cuon sach
nay tap
trung
vao cac
benh
thadng thay tren

cay ho
tieu
lam
giam nang suat, giam chat lupng
va gay
chet
cay lam ton hai ve
kinh
te cho
ngadi trong
tieu.
So
lieu
va
hinh
anh
trinh
bay
trong sach
la ket
qua
nghien cufu
cua
nhieu
the he
thay
c6
giao,
sinh vien
da! hoc, cao hoc,

va
nghien cufu vien
cua
nganh
Bao
veThUc
vat,
Cong nghe sinh
hoc,
thuoc
Bo mon
Bao
veThiic
vat.
Bp mon
Cong nghe
Sinh
hpc
cua
TrUdng
Dai hpc
Nong
Lam
thanh
pho Ho Chi
Minh,
tii
giai
quyet
nan

chet
cay
tieu tren
dao
Phu
Quoc
vao
thdi gian
dau cua
nhQng
nam
1980 den
giup
cac
tinh mien Trung,
Tay
Nguyen
va
Dong
Nam Bp vao
nhufng
nam
1990.
Cac
no
lUc
do
da
giup tfch
luy cac

thong
tin
lien quan
den
benh
hai
cay ho
tieu.
Mat
khac,
cac tai
lieu tham khao cung
ho trp
cho
cac
ket
qua
nghien cufu trinh
bay
trong sach
nay bao dam
ti'nh chi'nh
xac va
khoa
hpc.
Cac
tac gia
bien soan sach
nay
chan thanh

cam
Pn sif
dong
gop tu"
lieu
va
hinh
anh
minh
hpa
c6 gia tri
khoa
hpc cua
sinh vien
va
hpc
vien
c6
ten trong
tai
lieu tham khao
va
hinh
anh
cung
cap bdi
Cong
ty
Hoa
nong

Hop Tri
cho
viec hoan thien
cac npi
dung.
Day
la
Ian
xuat
ban dau
tien
nen
khong tranh dUpc nhCng thieu
sot,
cac tac gia
bien soan
rat
mong nhan
dupe su"dong gopy kien
cua
ngadi
dpc
nham hoan thien sach trong
Ian
tai
ban
sau.
Chan thanh
cam on.
Tac

gia
xii
I.
sd
Li/ac
CAY
H6
Ti§u
Cay
ho
tieu dang dupe trong
la
loai
cay hai
la
mam c6 ten
khoa
hpc
Piper nigrum L,
2n=52
hp
Piperaceae dupe
cho la mpt
loai
lai
giu'a
cac
loai
hoang
dai

Piper wiglitiiva Piper galeatum,
hoac
Piper wightii
va
Piper
tricho-
stachyon
(Ravindran, 2000).
Cay ho
tieu dupe
xem la "Vua cua cac
loai
gia vj"
con
gpi la
"vang den", diipc trong nhieu
d
cac
quoc
gia nam gan
xfch
dao
va
CO
khi
hau
nhiet
ddi. Hat
tieu
kho

dUpc sCr dung
nhu'
mpt
loai
gia vj
trong
thUc pham, tinh
dau
chiet xuat
tii hat
dUpc dung trong chQa benh
cho
ngUdi
va
c6
trong thanh phan
cua mpt so
my
pham.
Hinh 1: Cac
sdn
pham
sit
dung
tit
hat
ho
tieu
A:
Hat

tieu
den; B: Bot
tieu
den; C:
Hat
tieu
trdng;
D: Bot
tieu
trang;
E:
Hat
tieu
dong
goi;
F:
Tieu
non
Ci
ctiua;
G,
H,
I,
K:
Tieu
dung
lam gia vi
trong
ttiuc
plidm

^
1
Qucin tfio
Trudng Sa
Hinh 2: Dien tich cdy ho tieu vd
si/phdn
bo theo dja phUcfng
(Nguon: Tong
hcrp
tCr
cac
tai
lieu
pho bien
trong
nam 2012)
Vdi
Ijch
sCf
thi/cfng
mai
di/gtc
ghi nhan
til
3.000
den 2.000 nam
tri/dc
c6ng nguyen
tai
An 06. Nguon goc ho

tieu
dugfc cho la dOong Nam
Chau
A
vdi
cac dang hoang dai
tim
thay
trong
rCfng
nhiet
ddi
cua An 06, dao Java
cua Indonesia.
Dang
ho
tieu
du'ac
trong
tai
Malaysia va Indonesia dUpc du
nhap vao the ky
thuf
nhat sau cong nguyen vao
thdi
cue
thinh
cua vuong
quoc
Hindu.

Tai
Viet
Nam, cay ho
tieu
dupe
trong
lau ddi va hinh thanh
nhCfng vung
dja
ly
trong
ho
tieu
chuyen
biet
nhu
tieu
Phu Quoc,
tieu
Ho Xa
(Quing
Tri),
tieu
Tien Phtfdc (Quang Nam),
tieu
Oat d6 (Ba Rja-Vung Tau),
tieu
Lpc Ninh (Binh Phudc). TCr khi hat ho
tieu
Viet

Nam tham gia vao thj
tru'dng
xuat khau, da
thuc
day su" phat
trien
ca dien
tfch
trong
va quy mo
sin pham. Su chuyen dich co cau cay
trong
va quy mo cong nghiep,
djch
vu,
va du
lich
da lam thu hep dien
tfch
vung
tieu
Phu Quoc, nhu'ng hinh
thanh
nhu'ng vung
tieu
mdi
nhuChuSe.
Dich benh xly
ra
lien

tuc hang nam
va
miJc
dp dau
ta
cang cao do
thuoc
bao ve thac
vat
va cong lao dpng cang
tang
da
lam
thu
hep
dien
tfch
mot so vung ho
tieu
Quing Nam,Tay
Ninh,
va
Binh Thuan. Du vay, dien
tich
cay ho
tieu
cua ca nude khong
ngC/ng
tang
them

VLTpt qua dien
tfch
da quy hoach, dem lai sin lupng
tren
100.000
tan/nam,
va xuat khau dat
tren
14 ngan ti dong (nien vu 2012) va dang
difpc
trong
tai
22
tinh
thanh
trong
ca ni/dc.
B^ng
1:
Dien
tfch
trong
cay ho
tieu
tren
the
gidi
(hecta)
QU6CGIA
2007

2008
2009
2010
An
Dp 236.180 196.297 181.299
182.000
Indonesia 142.500 142.500 142.500
142.500
Vi^t Nam
50.000 50.000
50.000
50.000
Sri Lanl<a 29.976 30.655
30.506
30.714
Trung Quoc
21.000
22.687
23.545
24.000
Brazil
20.000
20.000
20.000
20.000
Malaysia 13.023
13.487
13.608
15.000
Madagascar

4.000!
4.000
4.000
4.000
2.800'
2.800
2.800 2.80Q ^
C^c
qu6c gia kh^c
3.000 3.000
3.000 3.000
Tong
522.479
487.926
473.785
476.514
(Theo
IPC,
2001-2010)
Bang
2:
San lirang
hat ho
tieu tren
the
gidi (Tan)
QUOC GIA 2007 2008
2009
2010
Viet

Nam 93.500 98.970 123.750
110.000
Indonesia
58.000
52.000
50.000 59.000
An Do
1
50.050 50.100 50.000 50.000
Brazil
42.500
41.000
40.700 34.000
Malaysia
20.000
22.000 22.000
23.50Q,.
Sri
Lanka
9.009 6.237
6.576
12.219
T6ng 273.059
270.307 293.026 288.719
(Theo
IPC,
2001-2010)
Bang
3:
Dien ti'ch

cay ho
tieu
tai 6
tinh trong tieu chi'nh
6
Viet
Nam
(VPA,2011)
Tinh
Dientich Dienti'chthu
trong
tieu
(ha) hoach (ha)
Nang
suat
Udrc
tinh
(tan/ha)
Shn lUqrng (tan)
Binh PhUdc 10.866 9.872 2,6
1
25.667
Oal<N6ng
7.915
6.085
2,15
13.096
Dong Nai
Ba
Ria

-
Vung Tau
Gia Lai
7.021
6.939
5.832
6.273
6.304
5.069
2,09
1,86
3,20
13.111
11.725
15.733
Dal<Lal<
4.898 4.384
2,67 11.715
Ci nude
50.000
2,5
100.000
4
II.
£)AC
DliM
HlNH
THAI CUA CAY H6
T|£U
I.Oacdiem chung

Cay
ho
tieu thupc nhom
cay
lau nam
c6
than dang
day
leo, phat
trien
ien cao
nhd vao
he re
bam (l<hi sinh)
dya
tren
tru
choai. Cay
c6 the
cao 20 met tao nen khung tan dang hlnh chop hoac
3 - 5
met tao tan hinh
tru
do
gidi han chieu cao tru choai. OUdng l<inh tan vung goc than c6 the
dat
2 met
lien quan den sCrc sinh trUdng
va
phat trien

cua
cay, cung nhii
mufc
do
cham soc
va ky
thuat trong. Cac giong
ho
tieu dang trong hien
nay thu'dng diidc
goi ten
theo
dia
phaong nhu tieu
Phu
Quoc, tieu
Ha
Tien,
tieu Vinh Linh, hoac theo dac diem hinh thai nhU tieu Se
la
Idn, Se
la
nho,
tieu Trau, tieu
Ba
Chia. Cac giong nhap
noi
dUdc xac djnh nhu Lada
Belangtung, Karimunda, Panniyur 1, Kuching,
va

Nam Vang. Nguon bien
dj trong
cac
giong
ho
tieu daoc tien doan
la rat Idn
giup
cho
cong
tac
chpn
loc
giong
c6
nhieu trien vong
va
ben canh, nguon
goc
giong cung
kho xac djnh
bdi
sUthfch iTng cao cua cac giong trong nhieu vung
dja ly.
2.
Oac diem nong hoc cua cay ho
tieu
Tai Viet Nam, cay ho tieu dUPc trong tC/ Nghe An den Phu Quoc bao
gom cac tinh vung cao nguyen den vung ven bien Bac, NamTrung bo. Tuy
theo giong

va
ijch sCr canh tac, cay
ho
tieu
da
thich nghi
vdi
vung
khi
hau
nhiet
ddi gio
mua
den
khong
khi
lanh
va am
Udt, mua
kho keo dai 4 - 5
thang,
mUa nhieu den
it
maa, trong
tdi
cao
dp
800 met tren mat bien (Gia
Lai),
va

tdi 19 dp
vT Bac (Nghe An). Thich nghi vdi khi hau
va
thdi tiet vung
ven bien hinh thanh vung tieu
c6
chat lupng
cao
nhU Phu Quoc,
Ba Rja -
Vung Tau.
Nhiet
do
thich
hdp cho cay
tieu phat trien tCr
20 -
30°C, nhiet
do
thap (10°C)
va
qua cao (40°C) deu anh hudng den sir phat trien cua cay,
sa
phan hoa mam hoa,
va
thdi gian chin cua
trai.
Laang mUa tCr 2.000
-
3.000

mm,
vdi am
dp
khong khi tCr 60
-
70%, khong
c6
gio bao. Lupng nUdc tudi
vao mua kho cho cay tieu rat quan trong
vi
day
la
thdi gian cay tich ICiy chat
kho vao hat va
bat
dau cho chu
ky
sinh trUdng mdi. Anh sang tan
xa
thich
hop
cho cay
tieu sinh tradng
va
phat trien,
dac
biet trong giai doan
sau
trong va kien thiet co ban. Nguon goc xuat xCrtCr vung rCrng nhiet ddi chufng
to cay ho tieu thich nghi vdi dieu kien che bong, lUdng hufu co cao, va \ia

am
nhung khong chiu ung. Cay
ho
tieu
cd the
trong tren nhieu loai
dat
khac
nhau,
CO
cau dat anh hudng rat Idn den sufc phat trien cua cay. Dat cd co cau
nang kho thoat nUdc, thanh phan cat nhieu kho giQ nUdc deu khong thich
5
hop cho cay
ho
tieu.
Oat
c6 pH
gan trung
tinh,
thanh phan hQu cO cao, tang canh tac
tCr
80 -
100 cm, thoat niidc tot, deu thi'ch
hop cho cay ho tieu phat trien.
3.
Dac diem hinh thai cay ho
ti§u
5.1. Rivabgri
Cay

ho
tieu hinh thanh
2
loai
re
chfnh,
re
l<hi sinh
va re hut
dinh dadng.
Rieng
re
coc,
re
cai,
chi c6 khi
trong bang
hat.
Re
khi
sinh phat sinh
tai cac dot
than chfnh, dot canh cap
1
c6 nhiem vu neo
dot than vao tru choai. Viec neo bam se giup
dmh hinh tan cay, gia tang chieu cao, chieu
rong
tan
cay,

va
giup cac canh cap
1
phat
trien.
Oac diem
re chi
phat sinh nhieu
tai
mat tiep giap
v6i tru
choai,
so re
nhieu,
it
phan chia va map chac.
Re hut dinh dudng phat sinh tai cac
dot than ngam,
tai vet cat
horn giong,
tao
nen bp re giup cay hut dinh dudng va
nUdc.
Re phat trien sau den
1,0-1,5
met
va Ian
den ria tan la, tap trung nhieu
d
do sau tCr 20

- 50 m. Ky thuat bon phan, tud\ va
tu
goc anh hadng rat Idn den sii phan bo he
re
trong vung tan cay.Tuy nhien, hadng
bo re
phat trien
an sau
xuong
dat se
giup
cay
chong chiu sUtan cong cua tuyen trung
va
nam gay benh, keo dai tuoi tho cua cay
tieu.
3.2. Than va
canh
ho tieu
Than
cay
tieu 6uac phan biet
bdi
mau sic, ki'ch thudc va
sU
phan canh. Than
chinh phat trien len
tren,
bam chat vao
tru

choai,
CO
nguon
goc tCf cay con
hoac
tu'
ngon canh tieu sau khi don day. Choi nach
6
than phat trien theo dang tan du. Choi non c6 mau vang nhat den
66
dam
tuy theo giong va thdi gian sinh trUdng. Giong Vinh Linh ngon non c6 mau
(Jo nhat den vang nhat, giong Lada Belantung c6 mau tfm nhat.Tuy nhien,
CO sU thay doi mau sac cua ngon non tuy theo dia ly vung trong
tieu.
Re
cay con
giam
canh
Re hut
dinh
dwdng
Hinh 4:
Choi
than non mau do nhat
Choi
than
non mau do
nhat
(A);

Than
chinh
7
nam
tuoi
(B);
Than
chinh
6
thdng
tuoi
c6 mau
xanh
Id cay (C).
Re
l(hisinh
bdm vao tru
choai
Hinh 3:
Cac
logi
ri
cay tieu
Hinh 5: Mau
sac
va hinh dang
ngon
non cua ho tieu
Canh
vwat

(canh
cap 1)
Canh
mang
trai
(canh
dc)
^^^^^
Canhlaan
Hinh 6: Cdc logi
canh
phdt trien tren cay ho tieu
- Canh vi/Ot: Dang canh moc thang phat trien len tren tao nen
l<hung tan cay. Canh hdp vdi than chi'nh mot goc nho hon 45° bam vao tru
choai.
Hom giong tC/ canh vUpt se cho trai cham nhung cho nang suat cao
va thdi gian canh tac dai.
- Canh laon: Hinh thanh tCrchoi sat goc, c6 long dai bo Ian tren mat
dat. Hom giong
tC/
canh luon cho trai cham nhUng nang suat cao.
- Canh mang
trai:
Dang canh moc nghieng, canh ngan, khuc khuy,
long rat ngan, goc do phan canh idn. Hom giong tCr canh mang trai cho
nang suat thap, mau gia coi, nhang mau cho
trai.
- Canh dinh: Dang canh phat trien tii phan dinh cua cay, long dai
moc ru xuong, ft dUpc dung lam hom giong. (Phan Quoc Sung, 1998).
3.3. Dang la

La tieu thuoc loai la don, c6 nhieu hinh dang nhu bau
tron,
thuon
dai hay hinh trai tim. La c6 gan hinh long chim, mpc
each,
c6 cuong la, kfch
thiidc, mau sac va hinh dang cua phien la thay doi tuy tCrng giong. Mat la
nhan bong, mat tren la c6 mau tiTxanh nhat den xanh tham, con mat dudi
la CO mau xanh luc.Tren cung mot cay, hinh dang la c6 nhieu khac biet theo
chieu cao cay. Sifthay doi mau sac, dp truong bong cua la giup chan doan
trinh trang dinh dadng va mufc dp bj benh cua cay.
8
Hinh 7: Cdc dang Id tieu
A,
B:
Mat tren va mat dudi la c6 hinh bau tron;
C,
D:
Mat tren va mat dUdi la c6 hinh thuon dai
3.4. Hoa va
chum
hoa
Hoa tieu thupc loai don tfnh
hay ludng ti'nh tuy theo giong, mau
trang,
c6 tCf 4 - 5 canh hoa, dai tC/ 7 -
12 cm, CO tir 20 - 60 hoa xep thanh
hinh xoan 6c tren
1
true tao nen chum

hoa.
Dadi moi hoa la mot la bac rung
sdm.
Xac dinh dac diem cua hoa cho
moi giong la co
sd
xac dinh bien phap
gia tang nang suat va dieu khien qua
trinh thu phan tang so lupng
trai/chum hoa.
Hinh 8:
Chum
hoa va hoa ho tieu
3.5.
Trai
tieu
Trai
tieu
thuoc dang
trai
hach, hinh cau c6 dadng
kfnii
tu'4-
8 mm,
hau nhu khong c6
cuong.
Tuy
theo
giong va dieu kien
canh

tac, kfch thadc
trai
khac
nhau.Trai
tieu
luc dau
mau
xanh, sau do chuyen
sang
mau
vang va
khi
chin c6 mau do. Mau sac cua v6
trai
giup xac djnh
thdi
diem
thu
hoach
cho sd che va che bien
tieu
den hay
tieu
so.
Thdi
gian
khi
xuat hien hoa day
du
den

khi
trai
chin keo dai
tC/
8
-
10
thang,
bao gom giai doan hinh thanh hoa va thu phan keo dai 1,0 - 1,5
thang,
phat
trien
trai
tLr4,0
- 5,5
thang,
giai doan
trai
chin
X\S
2,0
-
3,0
thang,
trai
dat du'dng
ki'nh
toi
da.Tuy
theo

vung dia ly va khi hau
thdi
tiet,
mua thu
hoach
tieu
bat dau
tCf
thang
1
keo dai den thang 4 hang nam.
10
III.
B|NH HAI
TRiN
CAY
H6
TI^U
TAI
VlfT
NAM
t.
Benh
Phytophthora
tren
ho
tieu
Benh
phytophthora
con

daoc
goi
nhu'
benh chet nhanh, benh heo
xanh, benh
chay
day, benh ba
trau.
Khong
tim
thay"dau hieu"cua tac nhan
gay benh ngoai dong ruong bang
mat
thUdng.Trieu chu'ng benh nhan dien
qua si/heo
ru
tCrng phan hay
toan
cay
v6i
la
mau
xanh
tai,
dom
nau den
tren
la,
trai
non heo

top,
rung dot phan than non,
re
thoi
den mem
nhun,
mach
dan ben trong than bien mau tii trang
sang
nau den
chay
doc theo
than.
Nghien
cufu
trieu
chufng cho
thay,
tac nhan gay benh tan cong ca phan
tren
mat
dat nha choi non, la, chum
trai,
canh, va than
chinh;
va phan du6i mat
dat
nhu"
re
va phan

than
ngam.
Benh
lam chet cay
tieu
hang
loat,
khong the
kiem soat
tai
cac vung ho
tieu
tCr
Nghe
An den Phu Quoc,
ti
le cay chet len
den 100%. Mac du
6\Sgc
dau ta nghien cufu Xii nhufng nam 1980 den nay,
nhtfng
nhufng hieu biet ve tac nhan gay benh van
chua
thanh he thong,
chaa
CO
bien phap phong
trC/
hieu qua va mot phan vi nguon
gene

khang
benh,
khang
P.
copsici
chUa
duoc xac
djnh.
Hinh
10:
Cac
dang
trieu
chvtng
benh
do
Phytophthora
capsici
gay
ra
tren
la
ho
tieu
A:
Vet
benh
tai
cuong
la;

B:
Tai
ban
Id;
C:
Tai
mep
Id;
D:
Tai
2
mep
Id,
E:
Tai
dudi
Id,
F:
Ld
khong
benh
(Nguyen
Than,
2004)
11
Mo trieu churng va tac hai gay benh
Tren
la:
Dom nau den
xuat hien vung

ria
ban la,
lien
ket
thanh
mang lam rung
la
khi dien tich vung benh chiem khoang 40% dien ti'ch
ban
la.
Vung benh cung xuat hien
tai
cuong
la
lam
la
rung
khi ban la van con
xanh.Tren
la
non,
vet benh
la
nhQng dom nau lam heo kho la nhanh chong.
Tren
cay,
la bj
benh khong
phu
thuoc

vao
vi tri
va
dp
cao cua
cay, trieu
chufng thudng quan
sat
thay
d
la
nam trong khoang
2 met
cao cua cay,
la
cua canh
bo
Ian tren mat dat
bj
benh nhieu hon tren cao.
Hinh
11:
Trieu
chCfng
benh
do
Phytophthora
capsici
gay ra
tren

ho
tieu
A:
Choi
nggn
khoe
mqnh;
B:
Choi
nggn
nhiem
P.
capsici
4
ngay;
C:
Ngon
bi heo kho
sau
nhiem
P.
capsici
30
ngay;
D:
Vet
benh
dtgc
trUng
tren

la non gay
heo
Id;
E:
Vet
benh
dac
trang
tren
choi
non gay
rung
choi
12
Tren
re:
MuTc
dp ton thi/ong re va
dp
sau vung re
bi
hai c6 lien quan
(jen trieu chufng phan tren mat
dat
cua cay ho
tieu.
+ Suxam nhiem qua re
to
den re chfnh se lam thoi phan than ngam
g^n

sat
mat dat dan den heo toan
bp
cay mot each nhanh chong.
^
Thoi
muc goc
than
va he
re
Hinh
12:
Trieu
chCtng
benh
Phytophthora
capsici
tren
than
tieu
+ Su xam nhiem than ngam
qua
re
nam sau hon 60 cm gay hoi
chufng vang la, giam sufc sinh trudng cua cay, chet sau
1
-
2
nam hoac
vao

mua
kho
nam sau
khi he re bj huy
hoai.
13
Hinh
13:
Cay
ho
tieu
bj
benh
chet
nhanh
A:
Trieu
chCtng
Id
vang
nhgt
toan
cay
la
da'u
hieu
re
nhiem
benh;
B:

La
heo
toan
cay
nhi/ng
khong
rung;
C:
Thoi
goc,
la
vang;
D:
Phan
re
ngam
thSi
den
phan
mo
Hinh
14:
Cay
ho
tieu
bj
benh
chet
nhanh
con

sot
Igi
tren
cay
chodi
va
lay
Ian
thanh
cum
tren
vUcfn
tieu
14
Tac nhan gay benh va
dacjdiem
gay benh
Tac nhan gay benh: Phytophthora palmivora var. piperis;
Phytophthora
palmivora MF4, tai Malaysia la Phytophthora botryosa,
phytophthora
parasitica var. nicotianae
(Varughese
va Anuar, 1992),
phytophthora
capsici Leonian.
P capsicidiuac xac dinh la nguyen nhan chi'nh gay benh chet nhanh
day
tieu
tai Indonesia (Manohara va cs,

2004),
Thai
Lan
(Tsao
va cs, 1997), Sri
Lanka
(Kularatne, 2002). d
Viet
Nam theo Nguyen Vinh TrUdng (2004), benh
vang la chet nhanh ho
tieu
d Quang Trj do Pythium sp., Phytophthora sp. va
Phytophthora
parasitica.lheo Nguyen
Tang
Ton (2005), benh chet nhanh ho
tieu
d Binh Phudc, Ba Ria - Vung Tau va Quang
Tri,
la do Phytophthora capsici
gay ra. Benh thudng xuat hien vao mua mUa, khi mUa nhieu va vao mua
kho,
khi nhiet dp cao. Benh nang d nhufng vudn
tieu
c6 dp
tuoi
Idn, do su
tich
luy nguon benh
trong

dat theo
thdi
gian, c6 vUdn ty le cay benh len tdi
75%,
ca biet c6 vUdn phai huy bo 100% cay
tieu
sau 4 - 7 nann cham soc.
Nguyen Vinh TrUdng va cs (2006) da xac dinh hinh thdc sinh san
hufu
tinh
cua P. capsici la di tan A2, noan bao tCf hinh thanh nhu la
bSng
chCrng
cho sU duy
tri
nguon benh
trong
vadn ho
tieu
tai Quang
Trj.
Nghien
cufu
cua Ngo Vinh Vien va cs, (2007) xac dinh Phytophthora capsici la tac
nhan chi'nh gay benh chet nhanh, chet chann
(thoi
re) cay ho
tieu
tai Oak
Nong,

nhiet dp 25 -
30°C,
pH
tu'
5 - 6 la dieu kien thi'ch hpp cho P. capsici
phat
trien.
Nghien cufu cua
Tran
Thi Huong (2009) (bang 4) cung cho thay
ton
tai dang lai A1 va A2 cua P capsici trong vUdn ho
tieu
trong
xen ca phe,
va chi
CO
A2
trong
vadn
tieu
thuan
tai
Dong Nai. Hinh thai cua nnau P capsici
phan lap
tren
vUdn
tieu
thuan va xen ca phe c6 mot so dac diem nha chieu
daivachieu rpng tui bao tCrco sU

khac
biet,
nhonhatia 14 - 27 x 9 - 14 (am
va I6n nhat la 17 - 30 x 10 -16
|am.
Ki'ch
thudc nuom
tui
bao tCf bien thien t(i
1,2 den 4,5 pm tuy
theo
mua mUa hay kho va dieu kien canh tac.
Kfch
thu-dc
16
phong thi'ch hep
tC/
3,5 \im den 9,5
[xm,
chieu dai cuong rung
trung
binh
71
Mm,
CO
khi dai den 127,0
|am.
Khong hinh thanh bao
tCf
vach

day
tren
moi
trudng
nuoi cay. P capsici c6 dang lai A2 va ca A1, c6 cung kieu
tiep
xuc
theo
kieu tui due bao xung quanh tui noan (Amphigynous).Tui noan hinh
cau
CO
mau cam sam vdi be mat
tron
lang hay xu
xi.
Cac mau P capsici phan
lap tu ho
tieu
c6 he spi phat
trien
phong len
tren
mat moi trUdng PGA va
CRA tao thanh dang hinh hoa hong hoac hoa thupc dupc c6 mep dang tia
ngan hoac
tia
dai.
Sau 6
ngay
u

tren
moi trUdng CRA, dudng kinh tan spi dat
15
85,4 mm;
82,9
mm
tren
PGA
va
tren
moi
trudng khoai
mi la
72,4 mm.
P.
capsici
tren
ho
tieu deu
c6
kha nang phat trien trong khoang nhiet
do
tii
12°C
den
350C,
nhang
d 250C
den
30°C la

khoang nhiet
do
thfch hop nhat.
d nhiet
do
thap hon
12°C,
chi mot so
ft
mau phan lap vao mua kho
6
vudn
tieu trong thuan phat trien. NhUng
d
35°C,
rat
ft
mau phan lap ton tai, ngoai
tru'
mau phan lap
d
vUdn tieu trong xen cay ca phe tai Dong Nai. Dac diem
hinh thai
va sa
phat trien cua
cac
mau
Phytophthora capsici
phu thupc vao
yeu

to
nhiet do. TCr
]2K
den
IS^C
toe
dp
phat trien
cua tan spi
tren
moi
trudng dinh dudng cham,
spi
manh, mpc thua, mau trang nhat, khong
c6
sU xuat hien cua
tui
bao tCr. Nhiet
dp 35°C he spi
co
cum lai, khong
c6 sa
xuat hien cua
tui
bao tCr, mau trang, xop, mpc bung tren mat moi trUdng.
BSng
4:
Mot so chi
tieu
so

sanh hinh thai P.
capsici
phan
lap
d
vadn tieu
thuan
va
xen
ca
phe.
Chi
tieu tiieo
doi
Phytophthora
or
vaim
xen
Phytophthora
d
virorn
thuan
(n
= 12)
(n=12)
Bien
thien
Trung
binh
Bien

thien
Trung
binh
Kich
thirac
tiii
bao
tir 15,3
-
27,8 X
21,6
X
12,7 15,3
-
26,8
X
21,
3
X
12,4
(urn)
9,3
-
15,5
9,4
-
15,5
Kich
thirac
nuom

tui
1,49
-3,87
2,69
1,66
-3,37
2,58
bao tu
(nm)
Kich
thuac
l6
phong 4,63
-7,78
5,65
4,20 -6,86
5,41
thich
tui
bao
tir
(nm)
Kich
thuac
chieu
dai
27,5
-
104,5
70,2

31,8 -
118,5
71,4
cuong
rung
tiii
bao
tir
(urn)
Dang
lai
A2
va
Al
A2
1
(Theo
Nguyen Thi Huang vdcs, 2013)
Dac diem
gay
benh:
P.
capsici
CO
the
gay trieu chifng chet
cay ho
tieu
6
thang tuoi

khi
nhiem 10^ dpng bao tCr/ml trong 20
-
30 ngay
d
dieu kien am
dp
cao. Dpng
bao tCr la nguon lay nhiem nguy hiem, trong vong
4
gid sau khi phong thfch
tii
tui bao tCr cac dpng bao tCf co kha nang xam nhap vao
mo
la, dinh
re
non,
va vet thapng tren than, choi non, md dau cho chu
ky
gay benh. Dpng
bao
tCf chi phong thich trong dieu kien am
dp
khong khi cao, nhiet dp thap, mUa
nhe,
trong gipt nadc. Mua kho,
he
spi
va tui
bao tCr la nguon gay benh

cho
re
ho
tieu.
Nguon benh ti'ch
luy
giam
dan
theo chieu sau, thadng
tii
tru
choai den mep tan
la va
sau
den 30 cm
la
vung nguon
P
capsici
hien dien
trong mua kho (bang 5).
6
dp sau nay,
he re
hut dinh daong cua cay ho tieu
16
tap trung nhieu va tuyen trung ky sinh
re
hien dien phong phu. Che dp
t\Jd'\

hay am
dp dat
vung
re
la
yeu
to
tac
dpng
den
siJ ton
tai va day tri
nguon
benh trong mua kho, phat tan vao mua maa.
Bang 5:
Nguon
P
cops/c; trong viidn
ho
tieu
bi
benh chet nhanh
vao mua
kho (thang 2/2011) (Huynh Tan True, 2011)
Do
sau lay
mau
dat
(cm)
Ti

1^
(%) mau
la bj
nhiem
P.
capsici
trong
mau
dat
Ti
If
trung
binh
(%)
Do
sau lay
mau
dat
(cm)
Tru
tieu
1
Try
tieu
2
Tru
tieu
3
Ti
If

trung
binh
(%)
0-5 23 7
16 15,3
5-10
13
2 9
8,0
10-20 11
2
0
4,3
20-30 13
0
7
6,7
>60
0
0
2
0,7
CV(%)
53,1
P
capsici
luon
ton tai
dadi
tan

cay
tieu,
mat so
trong phan
goc cay
tieu luon
cao hpn
vung
dat
giufa hang
cay
tieu (bang 6),
va vao mua
kho
P
capsici
khong hien dien giCa
cac
hang
cay
tieu.
Tran Thi HUdng
va cs.
(2013)
da
xac dinh
P capsici
tap trung
d
giCifa hang tieu

co
nguon goc xuat
phat
tii
goc
-
tan cay
tieu,
v6i khoang each Ian truyen qua nUdc mUa tCr 1,0
m
den
1,5
m. Do
do
can tao cac mUPng thoat nadc tot, nham
cat
nguon benh
lay Ian
va
phat tan trong mua mUa. Cay trong xen, nha ca phe, cung la "vat
can"su'phat tan P
capsici,
giup han che nguon benh tfch luy trong vUdn
tieu.
Hinh
IS:
Trieu
chCTng
gay ra
tren cac

mau la
tieu diing
6e
"bay
P.
capsici"
trong
dat,
nhiet dp
phong
sau
4
ngay
17
BSng
6: SLTtich luy nguon
P.
capsici
trong
mua kho va maa d hai mo hinh
trong ho tieu nam 2007 (TranThj HUdng, 2009)
VCing
\iy
miu
\i
mlu
\i
ti«u biy bj Mnh (%) theo
thing
iliu

tra (n = 9 tru)
VCing
\iy
miu
Things
Thing 4
Things
Thang
9
Thang
10
Thang
11
VCing
\iy
miu
Trong
thuan
Tr6ng
xen
Tr6ng
thuan
Trong
xen
Trong
thuan
Tr6ng
xen
Tr6ng
thuSn

Tr6ng
xen
Tr6ng
thuin
Tr6ng
xen
Tr6ng
thuin
Trong
xen
Trong
cua
1
tru t»u
11,1
5,4
15,3
9,8
24,2
18,0
34,7 32,5
36,9
34,1
35,6
35,2
Tai giura
4 tru
0,0 0,0
2,1
0,2

3,2
Q7
6,5
6,0
7,0
6,3
9,1
6,4
Nguon gene khang
P.
caps/c/trong cac giong ho tieu thupc loai
Piper
nigrum chua duoc xac dinh, nguon giong chong chiu benh de bj "tan cong"
d\Jd\p lac nguon benh c6 doc tinh cao. Dien bien cua benh chet nhanh
trong chu ky 1
nam c6 the thay doi theo vung sinh
thai,
dieu kien thcJi tiet,
CO cau giong trong vung, va bien
phap phong trCr da duoc ap
dung.
Trieu chufng cay tieu chet
hang loat thadng xay ra vao mua
kho,
dudi dieu kien nhiet do cao,
boc thoat hai nUdc nhieu, do he
re bj hu thoi nen cay nhanh
chong tan lui. Trong mua mUa,
hien taong cay chet xay ra khi
iUdng mira va so ngay mUa dat

cao nhat trong nam. Cay thadng
chet tCfng phan, hoac it nhanh,
rung la, rung dot hang loat d
phan tren cao cua cay.Tuy nhien,
kieu gay benh cua P.
capsici
tren
cay ho tieu la "tap trung", nghia la
khong ngau nhien, cay benh
xuat hien quanh nguon benh
Hinh16:
Trieu
chCfng
"teo top" ca
chum
ban dau tao thanh vung benh trditieuxanh la ddu hieu nhgn bietcay
(Anandaraj, 2000). Thdi gian Ci bibenh
chet
nhanh, I(h6ng the
phuc
hoi.
benh,
tfnh tCr luc P.
capsici
xam
Lifuy,
cayl<li6ng
biberili
vdichCim
trdi

nhiem thanh cong vao mo re
"binli
ttiUdng"
ton tgi
tren
cCing
1
tru
ctioai.
18
^^n khi xuat hien trieu chCrng chet nhanh phu thupc vao tuoi cay
tieu;
c6 the
1 _ 2 mua mua. Trong khi tren la, choi non, dot than non, va re to, P
capsici
chi can 4 -10 ngay da gay chay la, chet
choi,
rung dot than, va cay 6 thang
tuoi se chet sau 30 ngay bj xam nhiem (Nguyen Than, 2004). Dong bao tCr la
nguon xam nhiem chfnh trong mua mUa gay ra trieu chCrng benh rat nhanh
tren
la,
trai,
ngpn non, va dot than, trong khi he spi va bao tCrco the la nguon
xam nhiem vao re cay trong mua kho khi am dp vung re phu hop.
DUa vao so cay benh trong vadn c6 the du doan vj tri nguon benh
ton tai va dudoan trinh trang benh cua vadn sau nhieu nam. NhUvay, bien
phap"c6 lap" nguon benh ban dau se giup giam nguon benh tich luy va lay
Ian trong vadn va giQa cac vadn ho
tieu.

2.
Benh
vang la
Mo ta
trieu
chuTng va tac hai cua benh
Benh xuat hien rai rac tren vadn, mang tinh cue bp. Cay benh c6 la
vang ta phan dadi len tren tru
tieu,
canh la thaa, khong cd hoac rat it canh
non va canh mpc vapt, so canh mang trai ft, so trai tren chum tieu it. Re bi u
sang,
ft re to va thadng bi ha thoi muc nat. Cay benh rat de nhan biet trong
vadn.
Trieu chang vang la rat giong trieu chang thieu dinh dadng cua cay,
tuy nhien cay khdng hoac ft phuc hoi sau khi bdn phan va thadng trieu
chang vang ngay cang nang them. Benh lam tang chi phf phdng tra nhang
thadng it hieu qua, cay se chet dan sau mot vai nam cho
trai.
Hinh 17: Hoi chihig vang Id
19
Hinh
18:
Hoi
chCfng
vang Id
Tac
nhan
gay
benh

va dac diem gay
benh
Tac nhan gay benh thiidng do nhieu nguyen nhan khac nhau nha
do nam Fusarium oxysporum, Fusarium solani
f.
sp. piperis, tuyen trung gay
ha re, rep sap, va ca
P.
capsici. NhQng nghien cufu cua Iran Thi Thu Ha va cs
(2011),
da xac djnh Fusarium solani va Fusarium oxysporum c6 kha nang gay
benh vang la cho ho tieu trong tai Quang Tri, thdi gian Ci benh tCr 13 - 17
ngaysau chung.
Hlnh
19:
Mdu nam Fusarium
sp.
tren moi trUcfng PDA phan lap
tCtvUdn
ho tieu bi benh thoi re vang
Id
(A,
B).
Cay tieu sau khi chung nam dittic
cdch ly
(C),
cay ho tieu bi nhiem benh vang Id sau chung 14 ngay (D)
20
Chung tren cay tieu 2 thang tuoi trong vudn uom,
Fusarium spp. gay trieu chCrng vang la dau tien vao

ngay 14 sau chung va den 28 ngay toan bo la cay bj
vang.
Nam xam nhiem qua vet thaong cua re khi
trong mdi, khi xdi xao bon phan, qua vet thaong do
tuyen trung tao ra va u benh trong thdi gian ft nhat 15
ngay gay thoi den tang phan re, pha vd tQng phan
mo mach dan, gay bien mau he mach lam cay suy
nhuac dan den vang la. Nhieu nghien cdu cho rang
tuyen trung la tac nhan tao vet thaong cho Fusarium
spp.
xam nhiem.Trieu chQng vang la doi khi do rep ky
sinh tren re tao ra, rep chi'ch hut dinh dadng lam cay
kiet sdc vdi la vang nhat, giam sdc
song.
Cay benh
thadng xuat hien vao mua kho va thadng khong gay
chet hoac chet cham, sa lay nhiem
ta
tatao
nen vung
benh cue bo; mot den mot vai cay gan ke c6 trieu
chang benh. Nguyen nhan gay vang la thadng kho
xac dinh chinh xac, c6 nhieu tac nhan hien dien dong
thdi tren cay benh, vi vay"hoi chQng vang Ia"c6 the
daoc goi cho trieu chQng vang la cay ho tieu hien nay.
Ttian bi ttioi den
do Fusarium
Dai bao ttf
va tieu bao
tCf

Dai bao tCt tren
dinli sal nam
Soi nam ptian sinh
Hinh 20: Dai bao tdrvd tieu bao tvfnam Fusarium
spp.
3.
Benh
do
tuyen
trung
i^o ta
trieu
chuTng
va tac hai cua
benh
Tuyen trung ky sinh tren re ho tieu gom tuyen trung ngoai ky sinh va
"^Pi
ky
sinh,
chi'ch hut dinh dadng td re lam suy giam sdc khoe cua cay, gay
ton thaong re ngan can sa hap thu dinh dadng va nadc, gay vang la cue
bo hoac vang toan bo cay, gay heo tam thdi vao mua kho khi thieu nadc
CO
nhieu u badu tren re, vet tham den tai
badu,
hoac badu bi muc nat,
» " 21
CO
rat It re non
diTcfc

hlnh thanh. Hoi chufng vang la cay tieu c6 lien quan
den
miJc
dp re bi ton thaong do su ky sinh cua tuyen
trung.
Trieu chufng
sung
re
thudng do
tuyen
trung noi ky sinh gay
ra,
hoac
chi la vet
tham
nau
-
nau den
tren
re
do tuyen trung ngoai ky sinh tao ra.
Tac
nhan
gay
benh
va dac
diem
gay
benh
Cac mau dat va re ho tieu thu tai Vinh Linh, Gia Linh, va Cam Lo -

Quang Trj hien dien 27 loai tuyen trung ky sinh, trong do
Aphelenchus
avenae,
Rotylenchulus
reniformis,
Meloidogyne
incognita
la nhQng loai pho
bien va c6 mat so cao, rieng
Aphelenchoides
trivialis
la loai duoc ghi nhan
dau tien tren vung re cay ho tieu (Trinh Thi Thu
Thuy
va cs, 2012).
Theo
Nguyen Ba
KhUOng
(1983), d vung ho
tieu
mien Nam Viet Nam c6 15 giong
tuyen
trung
dUdc
phan lap nhu
Criconemoides,
Dolichodorus,
Helicoty-
lenchus,
l-lemicriconemoides,

Hemicycliophora,
Hirschmanniella,
Hoplolai-
mus,
Meloidodera,
Meloidogyne,
Pratylenchus,
Scutellonemo,
Trichodorus,
Trophonema,
Tylenchorhynchus,
va
Xiphinema.
Tai vung ho tieu Tan Lam -
Quang Tri, c6 4 loai tuyen trung gay benh nguy hiem la
Meloidogyne
incognita,
Rotylenchulus
reniformis,
Xiphinema
americanum,
Paratrichodorus
namus
(Nguyen
Ngoc
Chau,
1995). Nghien cufu cua
Phan
Thanh
San (2004)

di/a vao phan ufng cua cac giong cay chi
thi
vdi nguon
tuyen
trung
Meloido-
gyne duoc phan tach thuan va cau true cua van hau mon, da xac dinh
Meloidogyne
incognita
va
Meloidogyne
arenaria
ky sinh
tren
re ho
tieu
vung
Ba Ria - Vung Tau. Trong do
M.
incognita
chiem Uu the vdi 78,4% mau re bi
ky sinh va
M.
arenaria
ky sinh
tren
21,6% mau re
(Bang
7).
Bang

7:
Phan
Crng
cua mot so cay chi
thi
vdi
Meloidogyne
spp. phan lap tCr
re nhieu giong ho tieu
khac
nhau trong thi nghiem chung benh
(Phan
Thanh
Son, 2004)
Nguon
So biroii/gram re tiroi cua cac cay chi thi
Meloidogyne
Bong
Dau
Thuoc
la
6t
Du-a
hau
Ca
chua
tren re
vai
phgng
Kochin

0
0
92,6 ± 11,6
53,6 ± 10,7
17,5 ±1,5
67,0
±11,0
Se la Ian
0
0
98,0 ± 8,6
81,3 ±8,8
19,5 ±2,5
76,0 ± 5,0
VTnh
Linh
0
0
92,6 ± 14,2
67,6 ± 10,9
21,5 ±6,5
60,0 ± 9,7
Panniyur - 1
0
0
101,6+10,2
65,6 ± 12,5
17,0 ±4,0
80,3 ± 9,2
Lada

0
0
96,0 ± 5,5
83,3 ±8,0
13,6 ±0,8 48,5 ±2,5
belangtung
Khao
sat
tren
nhCfng mau
re tCr
nhieu
vung trong ho
tieu
khac
nhau,
Nguyen Van
Ngoc
(2004) da xac dinh
Meloidogyne
spp. ky sinh tren 100%
22
mau re cua tat ca cac giong ho tieu dang
canh
tac, rieng
Tylenchulus
hien
dien pho bien
d
vung

tieu
Ba Ria
-
Vung Tau va Dong Nai
(Bang
8).
Phan
ti'ch
mau dat va re ho tieu vung Lpc Ninh - Binh
PhUdcTran
Quoc
Hoai (2010),
xac dinh sii hien dien cua 19 loai thupc 16 giong tuyen trung
khac
nhau,
trong
do
Rotylenchulus,
Meloidogyne,
va
Tylenchulus
la ba giong tuyen
trung
pho bien trong 80 - 100% vUdn khao sat.
Diia
vao thanh phan giong
(genus)
va loai
(species)
ducfc djnh danh cho thay vung

re
cay ho
tieu
cung
hien dien nhieu loai tuyen trung ngoai ky sinh va npi ky sinh, trong do
Rotylenchulus
reniformis,
Meloidogyne
incognita,
Meloidogyne
arenaria,
va
Tylenchulus
semipenetrans
la loai tuyen trung ky sinh c6 djnh gay hai cho re
ho tieu va hien dien pho bien trong cac vung tieu tCr Quang Tri den Binh
PhUdc,
Ba Rja - Vung Tau. Mat so tuyen trung lien quan khong rp rang vdi
hpi
chufng benh vang la, tuy nhien cay bi benh vang la cp he re cSn cpi,
nhieu u
budu,
dau re npn bi tham den va muc nat tCrng phan.
Tuyen
trung lupn hien dien trpng vung re hp tieu va tap trung
nhieu
tu"
do sau 5 den 40 cm, vi re la noi cung cap dinh dudng cho tuyen
trung.
Cay

cang
tot,
re hut dinh dudng
cang
nhieu,
tuyen trung
cang
phat
trien
nhanh ve dan so. Mat so tuyen trung tren mot dcfn vj khoi lupng dat
(50g, 100 g)
hoac
khoi luong re
(1
g, 5
g), so badu
tren
don vi dai cua re (cm)
hay khoi lupng re (1g), so tuyen trung cai trong
1
butdu
re, la cac chi tieu
dung de danh gia mu^c do nhiem tuyen trung cua dat trong va cay ky chu.
Vi vay, bien phap kiem soat dan so
tuyen
trung
can thiic hien vao
thdi
diem
cay ho tieu cd toe dp phat

trien
cap nhat va luc tuyen trung tap trung vap
vung re nhieu nhat.
Tuyen
trung
nhanh chdng
tiep
can va xam nhiem vap
re
npn sau khi
cay dupe trpng va
thiet
lap quan the vdi nhieu the he cung tpn
tai.
Tuy
nhien ca cau dat, ngudn
hufu
co, vi sinh vat dpi khang
hpac
ky sinh cd anh
hudng den dan sp tuyen
trung.
Tuyen
trung re cay hp
tieu
it
dinh
c\J
d tang
<Jat

sau hon 60 cm, vi vay ky thuat trpng va cham sdc chp he re phat trien
thep
chieu sau se giup cay"thpat"su'xam nhiem cua tuyen
trung.
Tuyen
trung phat tan thep
nUdc
mUa,
nUdc
tudi,
dpng vat di lai
trong
vadn, cay gipng nhiem tuyen
trung,
hpac
dp cpn ngddi di lai vp
tinh
•T^ang
dat nhiem tuyen
trung.
Tan du
re
cd
tuyen
trung djnh cd, cay ky chu,
•T^ang
trdng trpng dat la nOi
\Uu
ton nguon tuyen trung tren vUdn hp tieu
h^ng nam.

23
Bang
8: Mat so tuyen
trung
Meloidogyne spp. va Tylenchulus sp.
trong
vung
re ho
tieu
Dja
diem Giong (ten
thu-ecng
gpi) Mat so
Meloidogyne
Mat so Tylenchulus sp.
dieu tra (so miu re phan tich) spp.
(con/lg
re)
(con/1
g re)
Trung
Cao nhat
Trung
binh Cao nhat
binh
Ba Rja -
Vinh
Linh
(n = 7)
285

334
388
414
Vung
Tau
Sela
nh6(n= 10)
135 280
234
296
(Binh
Gia,
Se
la Ion (n =
7)
265
326
497
630
Ngai
Giao,
Phil
Qu6e
(n = 5)
369 424 449 506
Hoa
Long,
Karimunda (n = 16)
273 373 384 433
Long

Dat)
Pennijur -
1
(n = 8) 305
394
269
437
Lada belangtung (n=10) 144 206 223 283
Dong Nai
VTnh Linh
(n = 5)
108
206 12
20
(Long
Sc
la
nho
(n
=
3)
117
146 102 146
Khanh)
Sc
la Ion
(n
=
4)
186

266 252 354
Phu Qu6e (n = 5)
220
254 374 520
Karimunda (n = 4)
188
254 89
106
Pennijur -
1
(n = 5)
220
300 268
334
Lada belangtung (n = 4)
189 240 106 166
Tieu
trau (n = 4)
229 246 292 554
Se ba chia (n = 4)
273
406 200
256
Binh
Duong Se
la
nho
(n
=
4)

279 310
0
-
(B6n
Cat)
Se
la Ion
(n
=
5) 330 360 0
-
Tieu
trau (n = 4)
308 340
0
-
Karimunda (n = 4) 297
340 0
-
Pennijur -
1
(n = 4) 343
366 0
-
Binh
Phudc
Vinh
Linh
(n= 16)
179

230 0
-
(Loc
Ninh,
Sela
nh6(n= 13)
237
506
230 338
Binh
Long)
Sela
lorn(n=
14)
382
460 256 336
Karimunda (n = 7)
264 410 390 605
Tieu
trau (n = 4)
305
376 0
-
Tay
Ninh
Vinh
Linh
(n = 4)
159 206
0

-
(Thanh
Dire
Se
la
nho
(n
=
5)
226 286
0
-
-
Go
Dau)
Se la
lorn
(n = 5)
139 306
0
-
Se ba chia (n = 5)
159 276
0
-
Tieu
trau (n = 5)
206 260 0
-
Lam

Dong
VTnh Linh
(n = 4)
373
496 0
-
(LOc
Nga,
Se
la
nho
(n
=
8)
180 268 0
-
Loc
Thanh - Se la
Icrn
(n = 9) 190 310 105 225
Bao
Loc)
Phu Qu6c (n = 4)
181 255 0
Tieu
trau (n = 5)
238 355 0
Dak Lak
VTnh Linh
(n = 5)

263
340
0
-
Cu
Jut,
Tieu
se (n = 5)
326 376 0
-
Cu
Mgar)
Tieu
trau (n= 10)
354 410
0
-
Binh
Thuan
VTnh Linh
(n = 5)
403 480 0
-
(Due
Linh)
Tieu
se (n= 10)
333 410
0
-

Tieu
trau (n = 5) 313 370 0
-
Kien
Giang Phu
Quoc
(n= 15)
177 270 0
-
(Kien
Tieu
se (n= 10)
115 166 0
-
Lucmg,
Ha
Tieu
trau (n = 5)
94 120 0
-
Tien,
Phu
Tieu
Ha
Tien
(n = 10) 174
210 0
Qu6c)
Quang Tri
VTnh Linh

(n = 5)
424
460 0
-
(Trich
ketqud
nghien
citu
cua
Nguyen
Van
Ngoc,
2004)
24
Re
thuoc
Id
c6
budu
tuyen
trung
Re
cay
dt c6
bUdu
tuyen
trung
Re
bong
vai

khong
cd
bUdu
tuyen
trung
Re
cay
dau
phdng
khong
c6
bUdu
tuyen
trung
Hinh
21:
Phan
Ctng
cua mot so cay ky chu chi thi cho sit gay
binh
cua
tuyen
trung
Meloidogyne
spp.
phan
lap tit re ho
tieu
25
Hinh

22:
SUdinh
ci/cua
Hfleloidogyne
spp.
trong
ri
ho
tieu
A:
Budu
va
ton
thMng
tqi
bUdu;
B:
Dinh
atcua
con
cdi
tri/dng
thanh
Meloidogyne
trong
bUdu
va
sU
bien
dang

re
do
butdu
phinh
to
(Phan
Thanh
San,
2004)
Cay
tieu
bi
benh
Re
bi
benh
vdi
budu
gay
bien
dang
re
4.
Benh
do vi rut
Doi vdi cay tieu thong thudng ngudi trong dung phaong phap
giam canh de nhan giong trong trong nridi va trong thay the nhufng cay tieu
chet trong vadn.Oacdiem phan hoa canh nhanh cua cay va sutac dpng cat
tia tao tan hang nam da lam lay nhiem vi rut theo kieu ngau nhien gia tang
mure dp nhiem benh tren dong rupng. Benh xuat hien tC/vUdn uom den sau

khi trpng va trpng supt thdi gian spng cua cay v6i trieu chufng benh tren ca
cay hpac mpt phan cay, vai canh hpac mpt it la khp phat hien va xCr ly.
Trieu chufng benh do vi rut gay ra
Oom hoa la: Be mat la cp cac dpm nhp mau vang nhat tdi vang dam vdi
nhieu vet hpai tCr, la npn khi nhiem nang se bi bien mau, mep la quan, gpn
spng.
Nhin tpan bp cay van phat trien binh thu'crng. Trieu chufng thudng
thay d la banh te cua nhanh
tieu,
va php bien tren cac vung hp
tieu.
Vang la gan
xanh:
d la npn va la gia. Oau tien la cac vet kham hinh trpn
mau vang nhat nam npi tiep nhau dpc thep gan chinh cua la (trieu chufng
nay thay nhieu d la npn). Khi benh nang, vet benh nga mau vang dam Ian
het ca phan thit la tap thanh vet vang trpng khi gan chfnh van cpn xanh.
Mep la quan, gPn spng,
CP
nhieu vet hpai tCr. Nhin tpan bp, cay van phat
trien binh thadng, nhang nhanh thi ngan khpng vapn dai.
Vang
la Kham la La nho
Caykhde
Hinh 25a: Cac dang
benh
do vi rut gay ra
28
La
nh6 bien dang: Hau het la npn CP kich

thu^cfc nhp khpng binh thudng, chop la cong
xuong,
be mat la nhan nhum, loi lom, c6 nhieu
vet kham, dom. Ngpn npn bi chun lai, cay sinh
trUdng cham hpac lun vang ca cay. Dpi khi
trpng cung mpt cay chi
CP
mpt phan hay mpt
vai nhanh tieu
CP
trieu chtTng benh,
CP
it chum
trai,
sp trai/chum ft, hat rat nhp.
Vang la: Phan vang la phan gi6i han giufa cac
gan chinh cua la, khpng phan biet rp rang giQa
vung benh va khpng benh, la khpng bien
dang.
Trieu chCrng thadng thay d la banh te va
la gia. Trieu churng benh gipng nhu cay thieu Khamxoan la
dinh dadng.
Dom vang nhat: Thadng thay d la gia, tren mat la cp nhieu vet ddm nhp
mau vang, dadng kinh khpang 1 - 3 mm, vet benh khpng hpai tCr, khpng
mat di, la khpng bj bien dang. Cay phat trien binh thadng.
Kham
xanh:
Gan la xanh, bien dang d mep la,
CP
nhieu vet xanh dam Ipi

jpm tren mat la, la xpan cupn vap phfa trpng. Nhanh phat trien yeu, chum
trai thaa, sp trai/chum ft
SP
vdi cay tieu khpng benh.
I
La
nho,
xoan
lun, kham
Hinh 25b: Cac dang
benh
do vi rut gay ra
29
•4
Dom hoa
Id
Ldnhddihmh
•
^ Xoan Id
Soqud/chuoi tieu bi benh vi rut
Si/kiidc
bietgiOra
cdnh benh vi rut
vd cdnh khoe, so cdnh qua giong nhau
nhWng
soqud/chuoi thi khdc nhau
Hinh
26:
Benh
vi rut

tren
cay ho
tieu
30
frinh
trang benh
vi
rut
tren
cay ho
tieu
Nghien curu
cua
Phan Dufc San (2003) xac djnh
c6 9
loai
vi rut gay
hai tren cay ho tieu tai cac vung tieu Phu Quoc
-
Kien Giang, Ha Tien
-
Kien
Giang,
Chau
Ddc -
Ba Ria
-
VungTau
va
Loc Ninh

-
Binh Phu6c.Trieu chiJng
benh xuat hien sdm trong giai doan vUdn
uam
sau giam hom
2
thang
va
sau trong
3-6
thang. Thi/c hien dieu
tra
882 cay tieu
d
Chau Dufc va
1115
cay
d
Binh Long, 1200 cay
d
moi vung tieu Ha Tien, Phu Quoc, va Lpc Ninh,
cho thay trieu chufng Dom
hoa la
xuat hien
pho
bien nhat trong cac trieu
chiJng benh
ghi
nhan. Cay tieu benh van phat trien binh thudng
va

khong
phai toan
bp
la, canh deu c6 trieu chCrng benh,
vi
vay rat kho nhan biet tinh
trang benh
cua cay
sdm. Trieu chtTng benh
va
mufc
dp
benh
vi rut
khong
lien quan den tuoi cay ho tieu va vung canh tac (bang 9,10), cay ho tieu
I6n
hPn
5
nam tuoi nhiem
vi rut
khong cao hpn cay nho hpn
2
nam
tuoi.
Vi vay,
can kiem soat
sU
Ian truyen nguon
vi

rut, con trung truyen benh, va
ve
sinh
cay benh cang sdm hieu qua phong benh cang cao.
Bang
9:
Ti le (%) la
tieu benh theo tCrng trieu chufng
d
cac vung dieu
tra
nam 2004
Trieu chufng Ti le
(%)
la nhiem benh tai
cac
vung dieu tra Trieu chufng
Chau
Dufc
Loc
Ninh
Ha Tien
Phu
Quoc
Dom hoa
la
56,6
36,1
44,6
32,0

Vang
la
gan xanh 12,7 30,2 10,1 30,1
La nhd bien dang
9,5 5,3 7,5
5,3
Vang
la
6,4 10,2 6,8 10,1
Dom vang nhat 4,8 10,5 20,0
-
Kham xanh
8,3
4,1
8,8
17,4
(-):
Khong
xac
djnh,
dieu
tra tren tieu 1-8
nam
tuoi
(Trich
ket qud
nghiin
ciru
cua
Phan

Di^cSan,
2004)
Bang
10:
Ti le (%) tru
tieu benh theo tCrng trieu chiTng
va
tuoi
cay d cac
vung dieu
tra
nam 2004
Trieu chufng Ti le
(%)
tru nhiem benh tai
cac
vung dieu tra theo
tuoi
cay
Chau
Dufc
Ldc
Ninh
Ha Tien
Phu
Quoc
1-2* 5-8
1-2
5-8
1-2

5-8 1-2 5-8
Dom hoa
la 58,7
54,5
33,3
38,8
44,0
45,2
33,3 30,7
Vang
la
gan xanh
12,0
9,2
21,5
38,8
12,3 7,8 31,5 27,7
La nho bien dang
10,2
9,7
10,3
0,3 1,8
12,7
3,3 7,3
Vang
la 12,8
0,0
14,3
6,2
13,2 0,7

19,2
6,7
£>6m vang nhat
0,0
9,7
15,0
6,0 20,3 19,7
0,0
0,0
J<hamxanh
4,0
13,5 1,0
7,2 4,8 11,8
7,8 22,2
(*):
1 -2namtu6i;
5-8namtu6i
(Trich
ket
qud nghiin
ci/u
cua Phan Diic
San,
2004)
Benh
vi
rut the hien
tren
cay
tieu khong theo

quy
luat,
c6
khi
la
benh xuat hien
tren
mot
so
nhanh phan dudi thap, hoac mot
vai
la
trong
cung mot nhanh, mot vai nhanh trong cung mot
cay
tieu.
Trong vUdn,
cay
benh xuat hien
va lay
Ian theo kieu "ngau
nhien".
Tai
Chau
Dufc
chi c6
trieu
chufngVang la gan xanh,
Kham
xanh, va

La
nho bien dang la
c6
su gia tang
ti
le la
nhiem theo
thdi
gian. Benh
vi
rut
gia
tang
vao
luc cay
phat
trien
manh than
la
cho den khi dUdc cat tia sau vu thu hoach hang nam.
Xac
dinh
tac
nhan
vi rut
bang
ky
thuat
phan
tCf

SCrdung
phadng phap
ELISA
vdi
cac
khang the don
va da
dong,
da
xac djnh TMV hien dien trong tCrng
trieu
churng benh ngoai dong ruong
(Bang
11).
TMV pho bien
tren
cay
ho tieu trong tai Binh
Phadc
va
Dong Nai,
va
la
mot trong nhQng
tac
nhan
tao nen
trieu
chufng benh.
Chung

dung
dich
vi
rut phan lap tCr mau benh
len cay
thuoc
la
{Nicotiana
tabacum),
da
xac djnh
CMV
hien dien trong mau benh Oom hoa
la
thu tCr
tieu
Vfnh Linh.
Bang
phuong phap
PCR
vdi
cac
primer chuyen
biet,
PYMoV
(Piper yellow
mottle
virus) da daoc
xac
djnh hien dien trong mau benh

Kham
xanh thu tCr
ho tieu trong tai
Gia
Lai. Nhu vay, CMV,TMV,
va
PYMoV
la
ba
loai vi rut duoc
xac nhan
gay
trieu
chuCng
benh
cho ho
tieu hien nay. Trieu
chCfng
benh
ngoai dong ruong
la
he qua
cua cac
tac dong phufc tap cua nhieu loai
vi
rut
khac
nhau cung hien dien trong
cay
(Lockhart,! 997;

Sarma,
2001).
Hinh
27:
Dien
di
DNA-PCR
vdi
cac
primer
chuyen
biet
giup
xac
dinh
sU
hien
dien
cua
vi
rut
PYMoV
trong
Id
ho
tieu
benh
(A),
(B):
Kich

tliUdc
DNA
dagc
tong
hap
la
450 bp, gel
agarose
1,5%,
80
V.
I
ladder
100
bp
2,
doi
chCfng
di/ong
3-5,
mau
benh
6, mau
khong
benh
32
Bang
11: Ket qua phan ti'ch mau benh bang
ELISA
Ten

Virus
Giong
Ket
quit
CaMV
Caulimovirus
-
PRSV
Potyvirus
-
TMV
Tobamovirus
+
WMV2
Potyvirus
-
INSV
Tospovirus
-
(-): Am
tinh
hay khong nhiem vi
rut
danh gia; (+): Duong
tinh
hay nhiem vi rut
Bing
12: Ti
le
xuat hien TMV trong

cac
trieu
chufng benh
(So
lieu dieu
tra
nam 2003)
Viing
dieu
tra
Ti
le
(%)
la c6 TMV theo trieu
chiiTng
benh
(Huyen)
Dom
Lanhd
Vang
Vang
06'm
KhSm
hoa
la
la
gan
la
vang
xanh

xanh
nhat
1
Binh
Long
-
54,2 13,8 7,3
1,3
1,5
0,0
1
Binh
PhUdc
I
Trcing
Bom -
46,7
3,0
0,1
0,0
0,0
0,0
1
Dong Nai
^
Chau
OiJc-
0,0 0,0 7,8
2,2
0,3

3,3
Ba Ria-
VCingTau
Xac
dinh
phi/orng
thuTc
Ian truyen benh
vi
rut
Vi rut
Ian
truyen
qua
nhieu phuong
each
khac
nhau, trong
do qua
horn
giong
la
con dudng chi'nh doi vdi nhieu loai vi
rut,
vi
cay
ho tieu thong
thudng
du'oc nhan giong
v6

tinh
bang hom giong (Son, 2003).
Ket
qua thi
nghiem vdi hom duoc chpn
c6
cac
trieu
chtrng benh
khac
nhau,
cho
thay
50%
so
hom
the
hien
trieu
chifng
vi
rut
sau khi nay
choi non.
Tuy
nhien,
hom
duqc
lay
tren

canh khong
c6
trieu
chufng benh
van
xuat hien
trieu
chCrng
benh
tren
choi 1 thang
tuoi
doi
vdi
giong tieu
Se, va
sdm
hon
doi
tieu
Vinh Linh
(Bang
13). Trieu chufng benh
tren
choi thadng
la
dom vang
nhat,
dom hoai tCr
tren

la than chi'nh
va la
nho bien dang
tren
choi non.
Nha
vay
CO
the ket luan rang
tac
nhan
gay
trieu
chufng dom hoa
la va la
nho
Ian
truyen
theo
he
thong
va
truyen nhiem theo hom giong.
PhUOng
thufc
Ian
truyen
qua hom giong lam
lay
Ian nguon benh

tCr
vung tieu nay
sang
vung
khac, khong
phu
thuoc
vao
vung
dja ly gay
kho
khan trong phong trCf.
Lockhart va
cs.
(1997)
va
Bhat va
cs.
(2003) cho rang rep
sap
{Ferrisia
virgata
*
33
va
Planococcus citri)
dacrc
xem
la
vector

(vat
truyen
lan)
truyen benh
vi rut
tren tieu
6
An
Do
va
Thai
Lan.
Kiem soat
rep
sap
la
bien phap ngan
can
su
phattan nguon
vi
rut
trong
mot
vUdn
va
giam si/gia tang mure
dp
benh tren
cay

ho
tieu.
Bang
13: Sif lan
truyen
vi rut qua
horn giong trong giam canh tieu
VTnh Linh benh theo trieu chufng
Horn Tieu
So
horn giong the hiien trieu chuTng benh
do vi
rut sau khi giam
Vinh Linh
ISngay 25ngay 35 ngay
45 ngay 45 ngay
50ngay
mang trieu
chuTng
IHS
IHB
IHS
IHB IHS IHB
IHS
IHB IHS
IHB IHS
IHB
Hoa
la
115

11
96 27
94 34
90 31
90 16 85
43
La
nh6
118
12
87 22
84
35 43
22 42 28 36
24
La nh6+
Hoa
u
131
20
80 13
77
38
59 25 52 25
47
30
Id
Oom vang
79
24

51
8 50 26 38 18 36 18
28
19
nhat
Khong benh 116
2
24
2 20
6 17 3 17 8 13
6
IHS:T6ng
so
horn
song,
IHB:Tong
so
horn
bi
benh.
mchke„uingMencaucu.WnTMNgocMn.20o,)
Trieu
chiJng
benh xuat hien tCf
hom
giong I<h6ng benh gom: Hoa la, la nh6.
Tac
hai cua
benh
vi rut

tren
cay
ho
tieu
Thiet
hai do vi rut gay ra doi v6i ho
tieu
la
lam
giam SLTC phat trien
cua
cay dua den
giam nang suat,
cay
bi
benh
vi
rut
thadng khong chet.
Sa
tich ICiy nguon
vi
rut
trong
cay
la c6
he
thong
va
lau

truyen
qua
nhieu
nam
gay hien taong xoan la, chun
dot
canh,
va lun cay.
Do
ky
thuat
cat
canh
tao
tan cung
vdi tac
dong
cua
phan
bon,
so
canh
mdi
xuat hien
doi khi
khong
hoac chaa
c6
trieu chiTng benh
lam cho sa

nhan dien miTc
do
benh
va
danh
gia thiet
hai
khong daoc
phu hop va
chi'nh
xac dan den
nhan thCrc
sai ve tac
hai
cua
benh.
Nghien ciJu
so
sanh giOfa
cay
tieu
c6
trieu chCfng benh
vi rut
nang
va
cay khong
c6
trieu chang benh,
cho

thay
sa
khac biet
len den
50%
nang
suat
hat
tieu thaong pham
6
cay
tieu
4 -
5 nam
tuoi,
lam
giam
thu
nhap
cua
ngacJi trong
tieu,
thiet
hai nay
tadng Crng
vdi
50%
tru
tieu
bi

chet hoan toan.
Kich thadc
va
trong laong
hat
tieu khong
c6 sa
khac biet giaa
cay
tieu
bj
nhiem
vi rut
nang
va
nhe. Vi
rut
lam
giam
rat ro
so
chum hoa/canh
va so
trai
con lai/chum,
tuy
nhien
sa
can bang dinh dadng
da

giup
cho so
trai
con
lai
tren
cay
benh nang
va
nhe
khong
c6 sa
khac biet
ve
trong laong
hay
kfch
thadc. Trong laong
1.000 hat
tieu
va ti le
tieu taoi/kho khong khac biet
Idn
34
giaa
cac
mau
so
sanh. Thiet
hai

kinh
te do vi rut gay ra la to Idn bdi
nang
suat
thu
daoc
chi
con
1/3 - 1/2 khi cay bi
benh
va dac
biet
cay
benh
rat
mau
gia
coi, lam
tang
chi phi dau
ta
phan
bon
va
thuoc
tra
sau.
Bang 14: So sanh
so
chum trai/canh, chieu

dai
chum,
so hat
va ki'ch thadc
hat
trung binh tren tieu Vinh Linh
4-5
tuoi trong
tai
Chau
Oac -
Ba
Ria
-
Vung
Tau
Ti?ih trang Tieu benh
nhe
Tieu benh nang
So Chieu
So
KichthUdc
So
Chieu
So
KichthUdc
chum/
dai hat/ hat
chum/
dai hat/ hat

canh chum chum l(hd(mm) canh chum chum l(hd(mm)
VUdn
(mm) (mm)
Vadn
1
- 103,4
33
- - 60,8 18 -
Vadn2
7,2
81,1
30 3,21 4,3 62,7 19
3,48
VLfdnS
10,2 84,8 29
-
5,5 62,8 19
-
Va6n4
9,5
80,7
28
3,18 4,9 54,3
17
3,33
VadnS 8,5 82,1 28
3,24 6,4 62,7 19 3,10
Trung
binh
8,9

86,4
29,6
3,21 5,3 60,7
18,4
3,3
-:
Khong c6
ketqui ITrlchkdqudnghl^noAi
cua
TrdnThiNgocHdn, 2004)
Bang
15: So
sanh nang suat tieu
hat
giaa
cay
tieu benh
vi rut
nang
va nhe
tren giong Vinh Linh
4 - 5
tuoi trong
tai
Chau
Ddc -
Ba Ria
-
VOng
Tau

rinh
Tieu benh
nhe
Tieu benh nang
*1?"9
"P P
P1000 P1000 Tile
P P
PI 000 PI 000
Ti
tuofi/
khol
hat hat
tUoi/ tUtfi/ khol
hat hat le
tru
tru
tuoi Idid
khd tru tru
tUOi
kho
tUori/
VUdn
(g)
(g) (g)
(g)
(g)
(g) (g)
(g)
khd

Vadn
1
10.840 4.247
70,0
32,0 2,6
3.970
1.329 66,8
30,5
3,0
Vadn2 10.358 4.622
98,3
41,9
2,2
5.885
2.356
97,5 41,0
2,4
Vadn
3
8.770 3.204
102,8
46,5
2,7
4.142
1.424
99,8 39,6
2,9
Vadn
4
11.220 4.658

91,5
39,0
2,4
3.085
1.117 87,1 36,0 2,8
Vadn5
12.230 4.973
92,3
36,0
2,5
7.674 2.636
94,3 38,8 2,9
Trung binh 10.684 4.341
91,0
39,1 2,5
4.951
1.772
89,1
37,2
2,8
(Trich
ketqud nghiin
cCru
cua
TrSn
Thi
Ngoc Hdn, 2004)
35